Không có triệu chứng rối loạn chức năng tâm thất trái Nồng độ norepinephrine tăng sớm trong sự phát triển của rối loạn chức năng tâm thất trái, và renin hoạt động huyết tương thường tăng ở những bệnh nhân được điều trị thuốc lợi tiểu. | Patterns of neurohormonal activation and prognosis Asymptomatic left ventricular dysfunction Plasma norepinephrine concentrations increase early in the development of left ventricular dysfunction and plasma renin activity usually increases in patients receiving diuretic treatment. Norepinephrine concentration in asymptomatic left ventricular dysfunction is a strong and independent predictor of the development of symptomatic chronic heart failure and long term mortality. Plasma concentrations of N-terminal proatrial natriuretic peptide and brain natriuretic peptide also seem to be good indicators of asymptomatic left ventricular dysfunction and may be useful in the future as an objective blood test in these patients. Congestive heart failure In severe untreated chronic heart failure concentrations of renin angiotensin II aldosterone noradrenaline and atrial natriuretic peptide are all increased. Plasma concentrations of various neuroendocrine markers correlate with both the severity of heart failure and the long term prognosis. For example raised plasma concentrations of N-terminal and C-terminal atrial natriuretic peptide and of brain natriuretic peptide are independent predictors of mortality in patients with chronic heart failure. Patients with congestive heart failure and raised plasma noradrenaline concentrations also have a worse prognosis. Other non-cardiac abnormalities in chronic heart failure Vasculature The vascular endothelium has an important role in the regulation of vascular tone releasing relaxing and contracting factors under basal conditions or during exercise. The increased peripheral resistance in patients with chronic heart failure is related to the alterations in autonomic control including heightened sympathetic tone activation of the renin-angiotensin-aldosterone system increased endothelin concentrations and impaired release of endothelium derived relaxing factor or nitric oxide . There is emerging evidence that impaired endothelial function
